Vapor deposition mask, organic electroluminescent display device, and manufacturing method therefor

ABSTRACT

In an organic electroluminescent display device comprising a wiring layer, an insulating layer, a first electrode, an organic electroluminescent layer, and a second electrode, wiring which conducts with a second electrode is arranged between light emitting pixels, and is provided either between an organic electroluminescent layer and the second electrodes, or on top of the second electrodes.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC 119 from Japanese PatentApplication, No. 2005-155615, the disclosure of which is incorporated byreference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a vapor deposition mask, an organicelectroluminescent (hereunder EL) display device, and a manufacturingmethod therefor. In particular the present invention relates to a vapordeposition mask in an active matrix drive organic EL display device of atop emission type, an organic EL display device, and a manufacturingmethod therefor.

2. Description of the Related Art

As a display device which can be made thin and lightweight as comparedto conventional cathode-ray tubes (CRT) and liquid crystal displays(LCD), a display device using organic EL elements has recently attracteda great deal of attention.

Since the organic EL element is self light emitting, it has variouscharacteristics such as, the visibility is high, there is no viewingangle dependency, a film substrate having flexibility can be used, andit is thin and lightweight as compared to the liquid crystal display.

In conventional organic EL display devices, for example an anode madefrom a transparent conductive film such as indium tin oxide film(hereunder ITO) is formed on an insulation substrate made from a glasssubstrate, and on this anode is formed an organic EL layer containing aluminous layer which generates light by recombination of electrons andpositive holes. Furthermore, on the organic EL layer is formed a cathodemade from Al or Mg—Ag alloy or the like. That is to say, on theinsulation substrate is formed the anode, the organic EL layer, and anorganic EL element comprising the cathode. Normally, the light generatedin the luminous layer of the organic EL layer is emitted from theinsulation substrate side, giving a so-called bottom emission type.

Furthermore, in order to realize a high definition display, advance isbeing made together with the organic EL element, for the development ofa display device of an active matrix type having switching elements suchas thin film transistors (hereunder TFT).

In the aforementioned bottom emission type organic EL display device, aswitching element such as a thin film transistor which controls thedrive voltage applied to the organic EL element, shuts out the lightgenerated in the luminous layer of the organic EL layer (has aninfluence on the organic EL layer). Hence the aperture ratio for thegenerated light with respect the entire bottom surface of the device isreduced.

Therefore, recently, so that the switching element does not cause ashadow, development is progressing for a top emission type organic ELdisplay device where the upper section common electrode is made as atransparent or semi-transparent optical transmission electrode, andlight is emitted from the upper electrode side.

In this case, for example the ITO constituting the common electrode ofthe upper section is formed at a low film forming temperature of 100° C.or less so as to not deteriorate the organic EL layer of the lowerlayer. Moreover in order to maintain the optical transmission, the filmthickness is made approximately 150 nm.

However, generally for transparent conductive bodies, the electricalresistance is large to become 30Ω per □ with the aforementionedconstruction. In the organic EL element for the current drive, a largecurrent is necessary at the time of high intensity emission, and due tothe wiring resistance and the large current of the electrical path, anexcessive load is applied to a power source.

That is to say, a voltage for where a voltage drop part comprising theproduct of the wiring resistance and the electrical current issubtracted from a power source voltage, becomes an effective voltage forthe organic EL device.

In this case, since a resistivity of a metal wiring inside the TFTsubstrate is 0.2 ohms per □, then for the wiring resistance and thevoltage drop in the electrical path, the high resistance of the commonelectrode becomes a predominant factor. Since the common electrode isconnected to the metal wiring inside the substrate at the outerperiphery of the screen, then at the closest portion (screen outerperiphery) and the remotest portion (the screen center) from theconnecting locus of the common electrode, the length of the electricalpath of the common electrode becomes different, so that the screencenter has a high resistance load caused by the common electrode.

Moreover, when the whole screen is lit, that is to say, when all thepixels are energized, the current of each pixel becomes superimposedfrom the screen center towards the common electrode connection portionof the screen outer periphery. Therefore, the high resistance of thecommon electrode becomes multiplied so that the voltage drop of thescreen center becomes greater than that for the screen outer periphery,and a difference occurs in the effective voltage of each of the organicEL elements, giving rise to brightness unevenness.

This brightness unevenness becomes a display quality loss. The largerthe display is, the more conspicuous the brightness unevenness is sincethe area for light emission is large so that a large current isnecessary and the common electrical path becomes long.

In order to solve the brightness unevenness which is apt to happen inthe top emission type organic EL display device, as shown in JapanesePatent Application Laid-Open Nos. 2002-318556 and 2004-207217, a methodis proposed where auxiliary wiring for the common electrode is arrangedat a TFT substrate. This is explained with reference to FIG. 15.

FIG. 15 is a schematic cross-section of a related art top emission typeorganic EL display device. A polysilicon island shape region 94 isformed on a glass substrate 91 via an SiN film 92 and an SiO₂ film 93. Agate electrode 96 made from Al is provided on the polysilicon islandshape region 94 via a gate insulating film 95 made from SiO₂ film. AnSiO₂ film 97 is provided so as to cover the whole surface, after whichopenings for the source-drain region are formed, and a source electrode98 and a drain electrode 99 are formed, to thereby form a TFT as anactive element.

Next, a positive type photosensitive polyimide is coated by a spincoating method, after which only the region corresponding to the sourceelectrode 98 is exposed and developed, followed by baking. As a result,a flat insulating film 100 having contact holes 101 corresponding to thesource electrode 98 is formed.

An Al film is deposited over the whole surface, after which a lowerelectrode 102 and auxiliary wiring 103 are formed by patterning in apredetermined shape. An SiO₂ film 104 is deposited over the wholesurface, after which a through hole 105 which exposes the auxiliarywiring 103, and an aperture area which exposes the lower electrode 102are formed.

Using a vapor deposition mask which is positioned so that a non-aperturearea corresponds to the auxiliary wiring 103, a hole injection layer, ahole transport layer, and a light emitting layer are vapor depositedunder heat in sequence to thereby form an organic EL layer 106. Thevapor deposition mask is then removed, and an upper electrode 107 madefrom ITO is deposited over the whole surface, and the upper electrode107 and the auxiliary wiring 103 are electrically connected.

Finally, as with a normal organic EL device, sealing is performed in adry nitrogen atmosphere, by means of a sealing plate 108 made from glassusing a UV adhesive, to thereby complete the top emission type organicEL display device.

In this manner, the upper electrode 107 made from ITO of a high specificresistance, is connected to the auxiliary wiring 103 made from Al of alow specific resistance. As a result, the voltage drop due to the upperelectrode 107 is reduced, and hence the display characteristics aregreatly improved.

However, the whole screen comprises the pixel aperture area where theorganic EL layer emits light, and the non pixel aperture area other thanthis, and if the space for the auxiliary wiring 103 and the through hole105 which are constructed in the non pixel aperture area is to be keptlarge, the pixel aperture area becomes small and an aperture ratio (aratio of the pixel aperture area with respect to the entire top surfaceof the device, same hereunder) is lowered so that the brightness isreduced. In the configuration of Japanese Patent Application Laid-OpenNo. 2004-207217, the aperture ratio is around 30%.

Furthermore, even if the non pixel aperture are is made to the minimumvalue of the processing limits, the higher the definition of the device,the greater an occupation proportion of the non pixel aperture area, sothat the aperture ratio is decreased. Therefore the configuration in therelated arts is less advantageous for obtaining high intensity of lightemission.

SUMMARY OF THE INVENTION

The present invention suppresses the area of a non pixel aperture areawith the connection configuration for the auxiliary wiring and thecommon electrode through the through holes, and therefore increases theaperture ratio.

A first aspect of the present invention is an organic EL display devicewhich comprises a wiring layer, an insulating layer, first electrodes,an organic EL layer, and second electrodes, each laminated in sequenceon a substrate, and all of the second electrodes are in a same layer.The organic EL display device further comprises a plurality of lightemitting pixels which radiate light emitted from the organic EL layerand transmitted through the second electrode. Furthermore, wiring whichconducts with the second electrode is arranged between the lightemitting pixels, and is provided either between the organic EL layer andthe second electrodes, or on top of the second electrodes, to give anorganic EL display device.

By arranging the wiring which conducts with the second electrode betweenthe light emitting pixels, the through holes become unnecessary, and thevoltage drop due to the second electrodes can be reduced withoutchanging the aperture ratio of the light emitting pixels.

In the above aspect, the plurality of the wiring, which conduct with thesecond electrode, may be configured so that film forming pattern of therespective wiring is continuous such that at least a portion of mutualpatterns is overlapped. That is to say, a pattern of a vapor depositionmask which is used for respective wiring is superimposed- and wiring ofa predetermined shape is optionally formed. As a result, it is notnecessary to provide the aperture area at a high density on the vapordeposition mask which is used, and hence the rigidity of the vapordeposition mask can be increased.

Furthermore, the configuration may be such that the wiring whichconducts with the second electrode has a so-called bus wiring in whichalternate wirings intersect each other and being tied in a regionoutside of the light emitting pixels. As a result, the voltage drop canbe reduced in the panel peripheral portion, where the current for eachpixel passes through the wiring to be concentrated, and the currentbecomes large.

In the aforementioned aspect, the wiring may be configured to have aplurality of shape elements, and at least one part of the shape elementsis mutually overlapped.

In the aforementioned aspect, the plurality of shape elements of thewiring may be arranged in mutually staggered form.

In the aforementioned aspect, the wiring may be configured such that theplurality of shape elements of the wiring which conduct with the secondelectrode include a plurality of types of shape elements, and at least apart of the shape elements of this plurality of types is mutuallyoverlapped.

Also in each of the aforementioned aspects, the voltage drop due to thesecond electrode can be reduced without having an influence on theaperture ratio. Furthermore, by superimposing the pattern of the vapordeposition mask which is used, and optionally forming wiring of apredetermined shape, it is no longer necessary to provide aperture areasin a high density on the vapor deposition mask which is used, and therigidity of the vapor deposition mask can be increased.

In the aforementioned aspect, the shape elements of the plurality oftypes of wiring which conducts with the second electrode comprise afirst shape element and a second shape element, and the second shapeelement is arranged on an outer periphery of a region where the firstshape element is arranged.

In the aforementioned aspect, the plurality of second shape elements maybe arranged with positions shifted from each other, on an outerperiphery of a region where the first shape element of the wiring whichconducts with the second electrode is arranged.

According to each of the above aspects, the voltage drop due to thesecond electrode can be reduced without influencing the aperture ratio.Furthermore, the current of each pixel passes through the wiring and thecurrent is concentrated, and the voltage drop in the panel peripheralportion where the current becomes large, can be reduced.

In a second aspect of the present invention, there is a vapor depositionmask which is used when constructing the organic EL display device, andwhich has a plurality of first aperture areas with a length L₁ and awidth W₁. The plurality of first aperture areas are arranged at a pitchP₁ in the length direction of the vapor deposition mask, and at a pitchP₂ in the width direction, and satisfy the relationships of L₁>P₁/2, andW₁<P₂/2.

As a result, it is not necessary to provide a high density aperture areaon the vapor deposition mask, and the rigidity of the vapor depositionmask can be increased. Moreover, the dimensional accuracy of theaperture pattern of the vapor deposition mask can be easily maintained.

In the aforementioned aspect, second aperture areas of length L₂ andwidth W₂ may be multiply arranged in the width direction of the vapordeposition, so as to satisfy the relationships of pitch P₃=P₂×m (where mis an integer of one or more), and W₂<P₃.

In the above aspect, third aperture areas of length L₃ and width W₂ maybe multiply arranged in the width direction of the vapor depositionmask, so as to satisfy the relationships of pitch P₃=P₂×m (where m is ainteger of one or more), and W₂<P₃.

According to these aspects, a desired wiring is obtained withoutproviding a high density aperture area for the vapor deposition mask.Consequently, the rigidity of the vapor deposition mask can beincreased, and the dimensional accuracy of the aperture pattern of thevapor deposition mask is easily maintained.

In the aforementioned aspect, third aperture areas arranged at a pitchP₃ may be arranged in the mutual length direction, with the positionshifted by δ satisfying δ<L₃.

By using such a vapor deposition mask, bus wiring can be laid anddeposited in optional directions.

In the aforementioned aspect, a slit aperture of width W₁ may beprovided in the vicinity of the width W₂ of the third aperture area ofthe vapor deposition mask.

In the aforementioned aspect, a slit aperture area in the vicinity ofthe width W₂ of the third aperture area of the vapor deposition mask,may be arranged at two or more locations, and the slit aperture area maybe arranged so that a pitch P₄=P₂×k (where k is an integer of one ormore) in the width direction of the first aperture area is satisfied,and the first aperture area is provided between a plurality of the slitaperture areas arranged in parallel.

By using such a vapor deposition mask, wiring wherein the third aperturearea and the first aperture area are superimposed is obtained by meansof the slit aperture.

Furthermore, since a highly detailed wiring pattern configuration isobtained without forming a high density aperture area in the vapordeposition mask, the rigidity of the vapor deposition mask can beincreased.

In the aforementioned aspect, the plurality of second aperture areas maybe provided on the outer periphery of a region where the plurality offirst aperture areas is arranged.

In the aforementioned aspect, the plurality of third aperture areas maybe provided on the outer periphery of a region where the plurality offirst aperture areas is arranged.

By using such a vapor deposition mask, the current of each pixel passesthrough the wiring and the current is concentrated, and a wiring isobtained which can reduce the voltage drop in the panel peripheralportion where the current becomes large.

A third aspect of the present invention is a manufacturing method for anorganic EL display device. The organic EL display device compriseslaminating on a substrate in sequence from the substrate side, a wiringlayer, an insulating layer, a first electrode, an organic EL layer, anda second electrode and forming all of the second electrodes in the samelayer. The display device has a plurality of light emitting pixels whichradiate light emitted from the organic EL layer and is transmittedthrough the second electrode. The manufacturing method comprises eitherbefore or after forming the second electrodes, the aforementioned vapordeposition mask is used to deposit wiring material on the substrate, andthen the aforementioned vapor deposition mask is moved with respect tothe substrate on which the wiring material has been deposited by(P₂/2)×(2n−1) (where n is an integer of one or more) in the widthdirection of the first aperture area of the vapor deposition mask, andfurther the wiring material is deposited, to thereby form a wiring whichconducts with the second electrode.

By the aforementioned manufacturing method, a desired wiring can beobtained without providing a high density aperture area on the vapordeposition mask, and the voltage drop due to the second wiring layer canbe reduced without having an influence on the aperture ratio.Furthermore, the rigidity of the vapor deposition mask is improved, anddimensional accuracy of the aperture pattern is easily maintained.

In the embodiments of the invention, by directly forming the auxiliarywiring on the upper face or lower face of the common electrode, theconnection between the common electrode and the auxiliary wiring isreliably obtained, and a through hole connection configuration becomesunnecessary. Therefore the aperture ratio can be increased, the voltagedrop due to the second electrode can be reduced, and a high intensitycan be obtained.

In particular, by making the aperture pattern in the vapor depositionmask for forming the auxiliary wiring, a mesh pattern by the aperturedimensions and the arrangement pitch, a desired wiring is obtained, andalso the rigidity of the vapor deposition mask is improved, and thedimensional accuracy of the aperture pattern is easily maintained.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will be described in detail basedon the following figures, wherein:

FIG. 1 is a schematic cross-section view of a top emission type organicEL device of a first example of the present invention;

FIG. 2 is an explanatory drawing of formation for inter-pixel auxiliarywiring;

FIG. 3 is an explanatory drawing of formation for an auxiliary wiringconnection portion;

FIG. 4A and FIG. 4B are explanatory drawings of a resistance drop effectof a common electrode due to the auxiliary wiring;

FIG. 5 is a schematic cross-section view of a top emission type organicEL device of a second example of the present invention;

FIG. 6 is a plan view showing an overall vapor deposition mask used in athird example of the present invention;

FIG. 7 is an enlarged view of a pattern region corner of the vapordeposition mask;

FIG. 8 is an explanatory drawing of a slit aperture area;

FIG. 9 is an explanatory drawing of formation for auxiliary wiring ofthe third example;

FIG. 10 is an enlarged view of a pattern region corner of a vapordeposition mask used in the fourth example of the present invention;

FIG. 11 is an explanatory drawing of a slit aperture area;

FIG. 12 is an explanatory drawing of formation for auxiliary wiring ofthe fourth example;

FIG. 13 is an explanatory drawing of formation for auxiliary wiring of afifth example;

FIG. 14 is an explanatory drawing of formation for auxiliary wiring of asixth example; and

FIG. 15 is a schematic cross-section view of a related art top emissiontype organic EL display device.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment of the present invention, a wiring layer, aninsulating layer, a first electrode, and an organic EL layer aresequentially laminated on a substrate. Either before or after forming asecond electrode, wiring material is vapor deposited on the substratevia a vapor deposition mask on which a plurality of first apertures oflength L₁ and width W₁ are arranged at a pitch P₁ in the lengthdirection thereof, and at a pitch P₂ in the width direction, so as tosatisfy a relationship of L₁>P₁/2, and W₁<P₂/2. Furthermore, the wiringmaterial is vapor deposited with the vapor deposition mask moved withrespect to the substrate by just (P₂/2)×(2n−1) (where n is an integer ofone or more) in the width direction of the first aperture area, andauxiliary wiring which conducts with a second electrode is formed.

First Example

Here, a top emission type organic EL display device of a first exampleof the present invention is explained, with reference to FIG. 1 throughFIG. 4.

As shown in FIG. 1, at first, pixel circuits 12 for controlling theelectric light emission of each pixel are formed on an insulationsubstrate 11 made of a glass, resin film, or the like after which pixelelectrodes 14 corresponding to each pixel circuit 12 are formed via aninterlaminar insulating layer 13.

These pixel electrodes 14 are electrically connected to the pixelcircuits 12 via contact holes (not shown) provided in the interlaminarinsulating layer 13.

Next, an organic EL layer 15 and a common electrode 16 made from ITO,are sequentially mask vapor deposited on each of the pixel electrodes14, after which, in order to evenly reduce the resistance of the commonelectrode 16, Al or Ag is vapor deposited using a vapor deposition mask,to thereby form auxiliary wiring 17 between the pixels (inter-pixelauxiliary wiring 18) and on the screen outer periphery (auxiliary wiringconnection portion 19).

FIG. 2 is an explanatory drawing of the formation for the inter-pixelauxiliary wiring 18. Using a vapor deposition mask 21 having lengthwisestripe shape aperture areas 22 arranged at a spacing corresponding tothe pixel pitch, inter-pixel auxiliary wiring 18 is formed on the commonelectrode 16 provided on the insulation substrate 11.

FIG. 3 is an explanatory drawing of the formation for the auxiliarywiring connection portion 19. Using a vapor deposition mask 23 havingtwo transverse stripe shape aperture areas 24, auxiliary wiringconnection portions 19 are formed outside of the pixel region of thecommon electrode 16 which is provided with the inter-pixel auxiliarywiring 18. The each auxiliary wiring connection portion 19 has widerwidth than the each inter-pixel auxiliary wiring 18.

In particular, in forming a multi-colored organic EL layer such as anRGB three primary color layer for obtaining a full color display, sincea space is provided between the light emitting pixels (between pixelelectrodes) for separately coating the colors, the auxiliary wiring 17is provided on this space so that it does not projectively overlap withthe pixel electrodes 14.

In the first example of the present invention, since the inter-pixelauxiliary wiring 18 is provided between the pixels, the resistance ofthe common electrode 16 made from ITO can be evenly reduced withoutchanging the aperture area (the aperture ratio) of the organic EL layer,and hence brightness unevenness can be effectively reduced.

Furthermore, since the auxiliary wiring connection portions 19 whichhave wider width than the inter-pixel auxiliary wiring 18, are providedoutside the pixel region where the most current flows, the voltage dropdue to the large electric current outside of the pixel region can bereduced.

FIG. 4A and FIG. 4B are explanatory drawings of a resistance drop effectof the common electrode due to the auxiliary wiring. FIG. 4A is anexplanatory drawing of a measurement method, and FIG. 4B is anexplanatory drawing of measurement results.

As shown in FIG. 4A, external connection terminals for the commonelectrode are provided at four corners of the panel. The resistances ofthe common electrode according to the distance up to the screen centerare measured, with the respective outside connection terminals as thestarting point.

For the common terminal in this case, ITO of a thickness of 300 nm isused, and a panel provided with auxiliary wiring made from Ag of athickness of 200 nm is measured. For comparison, a comparative example 1provided with a common electrode of ITO with a thickness of 300 nm, anda comparative example 2 of a bottom emission type which uses Al of athickness of 200 nm for the common electrode, are shown together.

As shown in FIG. 4B, in the comparative example 1, at a resistancedistribution at 18 to 24 ohms, an intensity unevenness is seen where thelow resistance screen corners emit in high intensity, while the highresistance screen center emits in low intensity.

On the other hand, in the case of the example 1 of the presentinvention, the resistance distribution becomes 3 to 4 ohms, which is alittle higher than the 1 to 2 ohms of the comparative example 2,however, the intensity unevenness is hardly visible similar to thecomparative example 2.

Second Example

A top emission type organic EL display device of a second example of thepresent invention is described with reference to FIG. 5. Since the vapordeposition mask which is used is the same as for the first exampleexcept that the position where the auxiliary wiring is provided isdifferent, then only the cross-section configuration is shown.

As with the first example, pixel circuits 12 for controlling theelectric light emission of each pixel are formed on an insulationsubstrate 11, after which pixel electrodes 14 corresponding to eachpixel circuit 12 are formed via an interlaminar insulating layer 13.Then an organic EL layer 15 is vapor deposited on the pixel electrodes14.

So that the organic EL layer is not deteriorated by moisture or oxygenand the like, the aforementioned vapor deposition mask 21 and a vapordeposition mask 23 are used, and inter-pixel auxiliary wiring 18 andauxiliary wiring connection portions 19 are vacuum formed in sequencemanner on the organic EL layer 15. Then after forming auxiliary wiring17, a common electrode 16 made from ITO is vapor deposited over thewhole surface.

The resistance of the common electrode 16 can be evenly reduced, and theintensity unevenness can be effectively reduced without changing theaperture ratio of the organic EL layer. Furthermore, the voltage dropdue to the large current outside of the pixel region can be reduced.

However, in the aforementioned first and second examples, forming thevapor deposition mask 21 having the aforementioned lengthwise stripeshape aperture areas 22 is difficult, and in particular, as stripe shapeaperture areas 22 become highly detailed (narrow pitch), slippagedeformation of the pattern accompanying a rigidity deterioration of thestripe portion occurs, and hence it becomes difficult to maintain thestripe shape.

In order to keep the stripe shape, the mask rigidity can be maintainedby thinning a number of the stripes, however it becomes necessary to adda vapor deposition process for the thinned portion.

Third Example

A third example of the present invention is described. However since thebasic structure is the same as for the aforementioned first example andsecond example, only the vapor deposition mask and the vapor depositionpattern are described.

FIG. 6 is a plan view showing the overall vapor deposition mask used inthe third example of the present invention. Furthermore, FIG. 7 is anenlarged view of a pattern region corner of the vapor deposition mask.The vapor deposition mask 31 comprises slit aperture areas 32 forinter-pixel auxiliary wiring, and slit aperture areas 33 and slitaperture areas 34 constituting auxiliary wiring connection portions.

FIG. 8 is an explanatory drawing of the slit aperture areas of thedeposition mask 31. The slit aperture area 32 for the inter-pixelauxiliary wiring is length L₁ and width W₁, and the slit aperture area33 is length L₂ and width W₂. The slit aperture area 34 comprises a slitportion 35 of length L₁/2 and width W₁, a rectangular portion 36 oflength L₃ and width W₂, and a connection portion 37.

As shown in FIG. 7, the slit aperture areas 32 for the inter-pixelauxiliary wiring are arranged at a pitch P₁ in the length direction, anda pitch P₂ in the width direction, thereof. Another slit aperture areas32 are further arranged in positions of half of the respective pitchesP₁ and P₂, giving a staggered array.

Furthermore, the slit aperture areas 33 and the slit aperture areas 34are arranged at a pitch P₃ in the width direction thereof.

The slit portion 35 provided in the slit aperture area 34 must bepositioned corresponding to the edge of the staggered array of the slitaperture areas 32, and hence P₂ is determined to be same to P₃.

Furthermore, some of slit aperture areas 34 are configured shifted by δin the length direction, so that a bus wiring in an optional inclineddirection can be formed.

FIG. 9 is an explanatory drawing of formation for the auxiliary wiringof the third example. The aforementioned vapor deposition mask 31 isarranged at an origin position and film forming is performed to therebyform inter-pixel auxiliary wiring elements 42 and auxiliary wiringconnection elements 45 and 47 (bus wiring element 45 and 47).

At this time, the origin position is set so that the slit aperture areas32 are positioned in the regions between the adjacent pixel electrodes14.

A film is formed at a position where the vapor deposition mask is movedby P₃/2=P₂/2 in the width direction of the respective slit apertureareas, so that an inter-pixel auxiliary wiring elements 43, and buswiring elements 46 and 48 are formed with being partly overlapped withthe inter-pixel auxiliary wiring elements 42 and the bus wiring elements45 and 47, respectively, which are previously formed. A plurality ofinter-pixel auxiliary wiring 41 and bus wiring 44 are thereby formed.

A patterning overlapped width D of the respective slit aperture areas isdetermined as follows from the relationship of the pattern dimensions ofthe aforementioned slit aperture areas.

An overlap D₁ in the length direction of the inter-pixel auxiliarywiring elements 42 and 43 becomes:D ₁ =L ₁ −P ₁/2

Furthermore, an overlap D₂ in the length direction of the inter-pixelauxiliary wiring elements 42 or 43, and the bus wiring elements 45 or 46becomes:D ₂ =L ₁ −P ₁/2

Moreover, an overlap D₃ in the width direction in each of the bus wiringelements 45 and 46, the bus wiring elements 47 and 48, or the bus wiringelements 46 and 47 becomes:D ₃ =W ₂−(P ₃/2)

One example of the numerical values for the case where the auxiliarywiring is formed with the aforementioned vapor deposition mask 31, for adisplay device of RGB tricolor configuration is shown in Table 1.

TABLE 1 Image size 64 mm × 48 mm 3.2 type Pixel number 320 × 240 QVGAspecification Pixel pitch  0.2 mm Definition 127 ppi Sub-pixel region0.067 mm × 0.2 mm  RGB tricolor configuration Pixel electrode 0.042 mm ×0.19 mm  Aperture ratio 60% Auxiliary P1  0.5 mm Optional wiring mask P20.134 mm Two times sub-pixel pitch P3 0.134 mm P3 = P2 L1  0.27 mm L1 >(P1/2) W1  0.02 mm Less than 0.025 mm between pixel electrodes L2  2.5mm Optional W2  0.1 mm W2 > (P3/2) Auxiliary wiring D1  0.02 mm D1 = L1− (P1/2) film overlapped D2  0.02 mm D2 = L1 − (P1/2) width D3 0.033 mmD3 = W2 − (P3/2)

In the third example of the present invention, since the stripe shapeaperture area in which each stripe shape aperture has continuous longshape is not provided, the rigidity of the vapor deposition mask isincreased, and the slippage deformation of the pattern can besuppressed. Furthermore, since the vapor depositions are performed twotimes, being the same as for the first example or the second example,the manufacturing processes are not increased.

Fourth Example

A fourth example of the present invention is described with reference toFIG. 10 through FIG. 12. However since the basic device structure is thesame as for the aforementioned first example or second example, only thevapor deposition mask and the vapor deposition pattern is described.

FIG. 10 is an enlarged view of a pattern region corner of a vapordeposition mask used in the fourth example of the present invention. Thevapor deposition mask 51 comprises slit aperture areas 52 forinter-pixel auxiliary wiring, and slit aperture areas 54 and slitaperture areas 53 constituting auxiliary wiring connection portions.

FIG. 11 is an explanatory drawing of the slit aperture areas. The slitaperture area 52 for the inter-pixel auxiliary wiring is length L₁ andwidth W₁, and the slit aperture area 53 for the auxiliary wiringconnection portion is length L₂ and width W₂. Moreover, for the slitaperture area 54, on a tip end portion of a rectangular portion 56 oflength L₃ and width W₂ there is provided three slit portions 55 at apitch of P₄, of a length L₁/2 and width W₁.

As shown in FIG. 10, the slit aperture areas 52 for the inter-pixelauxiliary wiring are arranged at a pitch P₁ in the length directionthereof, and a pitch P₂ in the width direction thereof. Moreover anotherslit aperture areas 52 are arranged in positions of half of therespective pitches P₁ and P₂, giving a staggered array.

Furthermore, the slit aperture areas 53 and the slit aperture areas 54are arranged at a pitch P₃ in the width direction thereof.

The slit portions 55 provided in the slit aperture area 54 must bepositioned at the edge of the staggered array of the slit aperture areas52, and hence the pitches are determined as P₂×3=P₃.

Furthermore, the plurality of slit aperture areas 54 is configuredshifted by δ in the length direction, so that a bus wiring in anoptional inclined direction can be formed.

FIG. 12 is an explanatory drawing of formation for the auxiliary wiringof the fourth example. Film forming is performed using theaforementioned vapor deposition mask 51 at an origin position, tothereby form inter-pixel auxiliary wiring elements 62 and auxiliarywiring connection elements 65 and 67 (bus wiring elements 65 and 67).

At this time, the origin position is set so that the slit aperture areas52 are positioned in the regions between the adjacent pixel electrodes14.

Next, a film is formed at a position where the vapor deposition mask ismoved by P₃/2=P₂×3/2 in the width direction of the respective slitaperture areas, so that an inter-pixel auxiliary wiring elements 63, andbus wiring elements 66 and 68 are partly overlapped, respectively withthe inter-pixel auxiliary wiring elements 62 and the bus wiring elements65 and 67 which are formed previously. Thereby, inter-pixel auxiliarywiring 61 and bus wiring 64 are formed.

Respective patterning overlapped widths D are determined as follows fromthe relationship of the aforementioned pattern dimensions.

An overlap D₁ in the length direction of the inter-pixel auxiliarywiring elements 62 and 63 becomes:D ₁ =L ₁ −P ₁/2

Furthermore, respective overlaps D₂ in the length direction of theinter-pixel auxiliary wiring elements 62 and 63, and the bus wiringelements 65 and 66 becomes:D ₂ =L ₁ −P ₁/2

Moreover, an overlap D₃ in the width direction in each of the bus wiringelements 65 and 66, the bus wiring elements 67 and 68, or the bus wiringelements 66 and 67 becomes:D ₃ =W ₂−(P ₃/2)

One example of the numerical values for a case where an auxiliary wiringis formed with the aforementioned vapor deposition mask 51, for adisplay device of a RGB tricolor configuration is shown in Table 2.

TABLE 2 Image size 64 mm × 48 mm 3.2 type Pixel number 320 × 240 QVGAspecification Pixel pitch  0.2 mm Definition 127 ppi Sub-pixel region0.067 mm × 0.2 mm  RGB tricolor configuration Pixel electrode 0.042 mm ×0.19 mm  Aperture ratio 60% Auxiliary P1  0.5 mm Optional wiring mask P20.134 mm  Two times sub-pixel pitch P3 0.402 mm  P3 = P2 × 3 L1 0.27 mmL1 > (P1/2) W1 0.02 mm Less than 0.025 mm between pixel electrodes L2 2.5 mm Optional W2 0.25 mm W2 > (P3/2) Auxiliary wiring D1 0.02 mm D1 =L1 − (P1/2) film overlap D2 0.02 mm D2 = L1 − (P1/2) width D3 0.049 mm D3 = W2 − (P3/2)

In the fourth example of the present invention, since the stripe shapeaperture area in which each stripe shape aperture has continuous longshape is not provided, the rigidity of the vapor deposition mask isincreased, and the slippage deformation of the pattern can besuppressed. Furthermore, since the vapor depositions are performed twotimes, being the same as for the first example or the second example,the manufacturing processes are not increased.

Moreover, in the fourth example, the slit aperture areas 53 and 54 areformed to be wide in width direction thereof. Therefore, in the case ofhigh definition, the space between the slit aperture areas 53, 54 pairs,that is, the support portion for the vapor deposition mask, can be madewide. Hence the rigidity of the mask can be further increased.

Fifth Example

A fifth example of the present invention is described with reference toFIG. 13. Since the basic device structure is the same as for theaforementioned fourth example, only the formation for the auxiliarywiring are described.

A transverse direction slit is provided in the central portion of theslit aperture area 52 in the aforementioned vapor deposition mask 51,and film forming is performed at an origin position using a vapordeposition mask made with cross-shape aperture areas, to thereby forminter-pixel auxiliary wiring elements 72 and bus wiring elements 75 and77.

At this time, the origin position is set so that the cross-shapeaperture areas are positioned in the regions between the adjacent pixelelectrodes 14.

Next, a film is formed at a position where the vapor deposition mask ismoved by P₃/2=P₂×3/2 in the width direction of the respective slitaperture areas, so that inter-pixel auxiliary wiring element 73, and buswiring element 76 and 78 are partly overlapped, respectively with theinter-pixel auxiliary wiring elements 72 and the bus wiring elements 75and 77 which are formed previously. Thereby, inter-pixel auxiliarywiring 71 and bus wiring 74 are formed.

In this fifth example, since the cross-shape aperture areas areprovided, a mesh shape inter-pixel auxiliary wiring can be formed, andthe transmission resistance of the common electrode can be furtherreduced. Moreover, even if tearing of the auxiliary wiring due to maskdefects occurs in one direction of the cross-shape wiring, a current issupplied from the other direction wiring, and hence there is no loss ofuniformity of the resistance of the common electrode.

Sixth Example

A sixth example of the present invention is described with reference toFIG. 14. Since the basic device structure is the same as for theaforementioned fourth example, only the formation for the auxiliarywiring is described.

In the vapor deposition mask of this example, compared to the singleslit aperture 52 in the aforementioned vapor deposition mask 51, atransverse direction slit is provided for connecting between adjacentsingle slit apertures 52 which are provided at staggered positions, togive a crank-shape aperture area. Film forming is performed at an originposition using this vapor deposition mask, to thereby form inter-pixelauxiliary wiring elements 82 and bus wiring elements 85 and 87.

At this time, the origin position is set so that the crank-shapeaperture areas are positioned in the regions between the adjacent pixelelectrodes 14.

Next, a film is formed at a position where the vapor deposition mask ismoved by P₃/2=P₂×3/2 in the width direction of the respective slitaperture areas, so that inter-pixel auxiliary wiring elements 83, andbus wiring elements 86 and 88 are overlapped, respectively with theinter-pixel auxiliary wiring elements 82, and the bus wiring elements 85and 87 which are formed previously. Thereby, inter-pixel auxiliarywiring 81 and bus wiring 84 are formed.

In the sixth example, since the crank-shape aperture areas are provided,then as for the aforementioned fifth example, a mesh shape inter-pixelauxiliary wiring can be formed, and the transmission resistance of thecommon electrode can be further reduced. Moreover, even if tearing ofthe auxiliary wiring due to mask defects occurs in one direction of thecrank-shape wiring, a current is supplied from the other directionwiring, and hence there is no loss of uniformity of the resistance ofthe common electrode.

In the above, various examples of the present invention have beendescribed, however the present invention is not limited or construed tothe conditions and configurations described for the respective examples,and various modifications are possible. For example, in theaforementioned respective examples, the configuration of the organic ELlayer is not shown, however this is appropriately selected from amongstknown organic EL materials in accordance with the luminescent colors.

Furthermore, in the aforementioned respective examples, ITO is used asthe translucent material constituting the common electrode. However thisis not limited to ITO, and other transparent oxide conductive materialssuch as IZO or ZnO may be used. Moreover, a metallic thin film of forexample Al or Ag formed as a thin film of approximately 20 nm may beused.

Furthermore also in the case of the aforementioned third example, theslit aperture area used for the inter-pixel auxiliary wiring may be across-shape aperture area or a crank-shape aperture area as in the fifthexample or the sixth example, thereby a mesh shape inter-pixel auxiliarywiring can be formed.

Moreover, in the aforementioned respective examples, a glass substrateis used as the substrate. However since the display devices of therespective embodiments are a top emission type, the substrate need notbe transparent, and a conducting substrate such as of stainless steel,or a nonconductive opaque substrate may be used.

Furthermore, in the aforementioned respective examples, the descriptionhas been for a full color display device. However the invention isapplicable to a different hue glass display device where a plurality ofcolors are appropriately combined. Moreover, the invention is alsoapplicable to the case of constructing a single color display device.

As an applicable example of the present invention, a two dimensionalmatrix display device is a typical example, but the present invention isnot limited to the display device, and can be applied to a large-sizesingle light source such as a light source for mood illumination.

1. An organic electroluminescent display device comprising a wiringlayer, an insulating layer, a first electrode, an organicelectroluminescent layer, and a second electrode that are laminated on asubstrate in sequence from the substrate side, wherein: the secondelectrode is a layer above the organic electroluminescent layer andcovers the organic electroluminescent layer; the organicelectroluminescent display device has a plurality of light emittingpixels radiating light that is emitted from the organicelectroluminescent layer and is transmitted through the secondelectrode; and the organic electroluminescent display device furthercomprises wiring that conducts with the second electrode, the wiringbeing arranged between the light emitting pixels and being provided atthe upper side of the organic electroluminescent layer either on top ofand in contact with the organic electroluminescent layer, or on top ofthe second electrode such that the wiring is in contact with the uppersurface of the second electrode.
 2. The organic electroluminescentdisplay device according to claim 1, wherein the wiring is configured tobe continuous such that at least a part of mutual film forming patternsof the respective wiring is overlapped.
 3. The organicelectroluminescent display device according to claim 2, whereinalternate wirings intersect so as to be connected to each other in aregion corresponding to a region outside of the light emitting pixels.4. An organic electroluminescent display device comprising: a substrate;a wiring layer; an insulating layer; a first electrode; an organicelectroluminescent layer; a second electrode; and wiring which conductswith the second electrode, wherein the second electrode is a layer abovethe organic electroluminescent layer and covers the organicelectroluminescent layer, the organic electroluminescent display devicehas a plurality of light emitting pixels radiating light that is emittedfrom the organic electroluminescent layer and is transmitted through thesecond electrode, and the wiring is arranged between the light emittingpixels, and is provided at the upper side of the organicelectroluminescent layer either on top of and in contact with theorganic electroluminescent layer, or on top of the second electrode suchthat the wiring is in contact with the upper surface of the secondelectrode.
 5. The organic electroluminescent display device according toclaim 4, wherein the wiring comprises a plurality of shape elements andat least a part of the shape elements is mutually overlapped.
 6. Theorganic electroluminescent display device according to claim 5, whereinthe plurality of shape elements are arranged in a mutually staggeredform.
 7. The organic electroluminescent display device according toclaim 5, wherein the plurality of shape elements includes a plurality oftypes of shape elements, and constitutes the wiring in which at least apart of the shape elements of the plurality of types is mutuallyoverlapped.
 8. The organic electroluminescent display device accordingto claim 7, wherein the shape elements of the plurality of typescomprise a first shape element and a second shape element, and thesecond shape element is arranged on an outside periphery of a regionwhere the first shape element is arranged.
 9. The organicelectroluminescent display device according to claim 8, wherein theplurality of second shape elements are arranged with positions thereofshifted from each other on the outside periphery of the region where thefirst shape element is arranged.
 10. The organic electroluminescentdisplay device according to claim 4, wherein the wiring comprises aplurality of shape elements, at least a part of the shape elements ismutually overlapped, and each shape element has a dimension exceedingthe dimension of each of the light emitting pixels by no more than thelength with which each of the shape elements overlap with each other.